An electronic control device in the related art includes a printed circuit board on which electronic components are mounted, a housing (the same as a storage case) that stores the printed circuit board, and a connector (hereinafter, referred to as “PCB connector”) including a plurality of terminals connected to the printed circuit board. The PCB connector has a tubular shape and includes a partition wall that isolates the housing from outside of the housing. Reference Document 1 discloses the terminals penetrate the partition wall in a liquid-tight manner.
Reference Document 1: JP 2017092281 A (pages 5 to 8, FIG. 2)
According to Reference Document 1 (board connector), a surface of the partition wall outside the housing is flat, and the terminals are press-fitted into through holes in the partition wall. For this reason, tensile stress is generated on inner peripheries of the through holes, and is particularly concentrated at positions close to the surface outside the housing in a range where the through holes abut corner portions of cross sections of the terminals. The tensile stress is further concentrated since the stress increases or decreases with temperature changes, which may cause a crack at the positions where the stress is concentrated.